Image forming method and image forming apparatus

ABSTRACT

The image forming method includes a recording step of recording an image on an image recording layer of an image recording medium according to image data, a material setting step of setting a coating film to be provided on the image recording layer according to glossiness data indicating glossiness of the image reproduced by the image data, a condition setting step of determining a condition of a surface processing of the coating film by considering the set coating film and according to the glossiness data, and a processing step of performing the surface processing of the coating film in accordance with the determined surface processing condition.

RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.10/942,927, filed Sep. 17, 2004 and it is incorporated herein byreference.

BACKGROUND OF THE INVENTION

The present invention relates to a technical field of image formation,and more particularly to an image forming method and an image formingapparatus capable of forming a high-quality image provided with glossappropriate for the contents etc. of the image.

Various surface processing techniques are known for finishing imagesurfaces glossy like those of photographic prints or properlycontrolling surface glossiness so that images look fine, so as to addenhanced value to images (hard copies) outputted by ink jet printers andelectrophotographic printers.

For example, JP 10-319621 A discloses a method of forming an image byelectrophotography, in which, after formation of a color image, atransparent layer of inorganic oxide fine particles with a refractiveindex of 1.4 to 1.6 and water-soluble resin is formed so that therefractive index of the toner used to form the image, the refractiveindex of the inorganic oxide fine particles, and the thickness of thetransparent layer are in a given relation, so as to form a color imagehaving uniform gloss like a photographic print.

JP 2001-92171 A also discloses a method of forming an image byelectrophotography, in which silicone oil that is temperature-controlledso that its viscosity is 0.1 P or more and its surface tension is 15dyn/cm or less is applied onto the surface of fixed toner layers, so asto prevent offset and to form an image provided with sufficient glosslike a photographic print.

Further, JP 2000-264481 A discloses an image forming device forelectrophotographic image recording, in which, after formation of animage, the image formed surface is brought into contact with a rollerhaving a roughened surface, with the contacting force being controlledaccording to a selected degree of gloss and considering the material onwhich the image is formed (transfer material), so as to form an imagehaving reduced glossiness and comfortable to see.

SUMMARY OF THE INVENTION

The methods disclosed in JP 10-319621 A, JP 2001-92171 A, and JP2000-264481 A are capable of adding enhanced value to images byproviding image surfaces with gloss like that of photographic prints orby reducing glossiness of image surfaces to improve viewability.

Now, images produced by such printers contain a great variety ofcontents and it is therefore desired that suitable glossiness can begiven with high degree of freedom in accordance with the contents ofimages in order to obtain more highly value-added images.

An image will contain glossy objects (contents forming the image) andobjects not glossy at all. Accordingly, in order to form ahigher-quality image with enhanced image texture, it is desirable toprovide different degrees of gloss in different areas of the imagedepending on the objects recorded in the areas.

However, the methods disclosed in the patent documents cited above donot allow high degree of freedom to select the degree of glossiness, sothey often fail to provide glossiness suitable for the image. Moreover,the methods disclosed in JP 10-319621 A, JP 2001-92171 A, and JP2000-264481 are only capable of providing uniform glossiness on theentire image surface but are incapable of providing different degrees ofglossiness in accordance with the contents recorded in different areasof the image. Also, in controlling image surface glossiness inaccordance with the contents of images, obtaining desired glossinesswith various kinds of recording media requires that images be processedunder conditions suitable for target glossiness. However, theconventional techniques are incapable of such glossiness control.

The present invention has been made to solve the problems of theconventional techniques, and an object of the present invention is toprovide an image forming method and an image forming apparatus capableof highly freely providing suitable glossiness in accordance with thecontents of an image, e.g. objects recorded in the image, and morepreferably, capable of providing glossiness appropriate for differentcontents recorded in different areas of the image, so as to form ahigh-quality image that properly expresses texture.

In order to attain the above-mentioned object, a first aspect of thepresent invention provides an image forming method comprising: arecording step of recording an image on an image recording layer of animage recording medium according to image data; a material setting stepof setting a coating film to be provided on said image recording layeraccording to glossiness data indicating glossiness of the imagereproduced by said image data; a condition setting step of determining acondition of a surface processing of said coating film by consideringsaid set coating film and according to said glossiness data; and aprocessing step of performing the surface processing of said coatingfilm in accordance with said determined surface processing condition.

Preferably, said glossiness data indicates a degree of gloss for eacharea of the reproduced image.

Preferably, said material setting step sets said coating film accordingto a table using said glossiness data and said coating film asparameters.

Preferably, the surface processing in said processing step is performedby heating means for heating a surface of said coating film and pressingmeans for pressing a pressing member against a surface of said coatingfilm, and said condition setting step determines said surface processingcondition according to a table using, as parameters, in addition to saidglossiness data and said coating film, at least one of heatingtemperature by said heating means, heating time by said heating means,pressing force by said pressing means, surface roughness of saidpressing member, and pressing time by said pressing means.

Preferably, said heating means heats the surface of said coating filmwhile locally controlling the heating.

Preferably, said recording step records said image at a resolution whichis an integral multiple of that of said surface processing.

Further, in order to attain the above-mentioned object, a second aspectof the present invention provides an image forming apparatus comprising:an image recording medium feeding unit which feeds an image recordingmedium; an image recording unit which records an image on an imagerecording layer of an image recording medium according to image data; acontrol unit which sets a coating film to be provided on said imagerecording layer according to glossiness data indicating glossiness ofthe image reproduced by said image data and determines a condition of asurface processing of said coating film by considering said set coatingfilm and according to said glossiness data; a coating film laminatingunit which laminates said coating film set by said control unit on saidimage recording layer; and a surface processing unit which performs asurface processing of said coating film in accordance with said surfaceprocessing condition determined by said control unit.

Preferably, said glossiness data indicates a degree of gloss for eacharea of the reproduced image.

Preferably, said control unit sets said coating film according to atable using said glossiness data and said coating film as parameters.

Preferably, said surface processing unit includes heating means whichheats a surface of said coating film and pressing means which presses apressing member against a surface of said coating film, and wherein saidcontrol unit determines said surface processing condition according to atable using, as parameters, in addition to said glossiness data and saidcoating film, at least one of heating temperature by said heating means,heating time by said heating means, pressing force by said pressingmeans, surface roughness of said pressing member, and pressing time bysaid pressing means.

Preferably, said heating means heats the surface of said coating filmwhile locally controlling the heating.

Preferably, said image recording unit records said image at a resolutionwhich is an integral multiple of that of said surface processing by saidsurface processing unit.

According to the image forming method and the image forming apparatus ofthe present invention, it is possible to highly freely provide suitableglossiness in accordance with the contents of image areas, like objectsrecorded in the image, and more preferably, to provide different degreesof glossiness appropriate for the contents in different areas of theimage, so as to form a high-quality image (hard copy) that properlyexpresses texture.

This application claims priority on Japanese patent application No.2003-324363, the entire contents of which are hereby incorporated byreference. In addition, the entire contents of literatures cited in thisspecification are incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual view showing an image forming apparatus thatimplements an example of the image forming method according to thepresent invention;

FIG. 2 is a conceptual view showing an example of an image formed theimage forming apparatus shown in FIG. 1;

FIG. 3 is a schematic sectional view of a hard copy formed by the imageforming apparatus shown in FIG. 1 used to describe a physical factor ofthe surface glossiness;

FIG. 4 is a flowchart showing an image forming method of the imageforming apparatus shown in FIG. 1;

FIG. 5A is a diagram showing an example of a material setting tableemployed in the image forming apparatus shown in FIG. 1; and

FIG. 5B is a diagram showing an example of a conditioning setting tableemployed in the image forming apparatus shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The image forming method of the present invention is now described indetail referring to the preferred embodiment illustrated in theaccompanying drawings.

FIG. 1 is a conceptual diagram illustrating an image forming apparatusthat implements an example of the image forming method of the presentinvention.

An image forming apparatus 10 of FIG. 1 records an image by ink jet onthe surface (on an image recording layer) of an image recording medium12 (hereinafter referred to as recording medium 12), laminates a coatingfilm 14 on the image recording surface, and then processes the surfaceof the coating film 14. The image forming apparatus 10 basicallyincludes a medium feeding unit 16, a cutter 18, an image recording unit20, a coating film laminating unit 22, a surface processing unit 24, anda control unit 26. Though not shown in FIG. 1, the image formingapparatus 10 may further include any components that would be providedin image forming apparatuses using sheet-like materials or apparatuseshaving sheet-like material laminating process, e.g. means for conveyingthe recording medium 12 or coating film 14, conveyance guides,positioning means, various sensors, etc.

The medium feeding unit 16 (hereinafter referred to as feeding unit 16)feeds the recording medium 12 on which an image is to be recorded(formed).

In the example of FIG. 1, a long strip of recording medium 12 wound toform a medium roll 28 is loaded in the feeding unit 16 and a feedingroller pair 30 draws out the recording medium 12 from the medium roll 28and feeds it downstream.

As shown by dotted line in FIG. 1, a plurality of medium rolls 28 ofdifferent recording media 12 are prepared. The feeding unit 16 feeds arecording medium 12 specified by, e.g. an input instruction from anoperator, from the corresponding medium roll 28. A single kind ofrecording medium 12 may be prepared, or two or more kinds of, or anarbitrary number of, recording media 12 may be prepared. The imageforming apparatus 10 may be constructed to allow loading of only asingle medium roll 28 in the feeding unit 16, and then an operator etc.will set an appropriate one depending on the image to be formed (a hardcopy).

In the present invention, the recording medium 12 is not limited to aparticular kind and any kind of recording medium can be used as long asit has a base and an image recording layer (a colorant layer (includinga region for holding (to be impregnated with) ink or toner in the base))and conforms to the image recording method employed in the imagerecording unit 20 described later. For example, the recording medium 12can be plain paper or ink jet paper when ink jet process is used, or itcan be plain paper when electrophotography process is used, or it can bephotographic paper when a photographic printer is used.

The thickness of the recording medium 12 is not particularly limited,either, which can be in a common range for the recording medium 12,preferably from 50 μm to 150 μm.

The recording medium 12 fed from the feeding unit 16 is moved to theimage recording unit 20 by the feeding roller pair 30 and a scanningconveyer roller pair 32 that belongs to the image recording unit 20. Thecutter 18 is located between the feeding roller pair 30 and the scanningconveyer roller pair 32.

The cutter 18 is a conventional cutter for cutting sheet-like materials.The conveyance of the recording medium 12 by the feeding roller pair 30and the scanning conveyer roller pair 32 is once stopped when the lengthof the recording medium 12 beyond the cutter 18 becomes equal to thesize of the image to be formed (the size of the hard copy). Then thecutter 18 cuts the recording medium 12 to form a cut sheet of the imagesize and then the scanning conveyer roller pair 32 restarts to conveythe recording medium 12 downstream to the recording position.

The image recording unit 20 (hereinafter referred to as recording unit20) is an image recording means that records an image by ink jet on thesurface (image recording layer) of the recording medium 12. The imagerecording unit 20 includes scanning conveyer roller pairs 32 and 34 andan ink jet recording head 36 (hereinafter referred to as recording head36) located between the scanning conveyer roller pairs 32 and 34.

The recording head 36 is a ink jet recording head, which can be athermal ink jet recording head, a piezo-type ink jet recording head, oran electrostatic ink jet recording head, for example.

The recording head 36 is a so-called line head that has rows of nozzles(ink discharge ports) having a length exceeding the maximum size of thewidth direction of the corresponding recording medium 12 (the directionperpendicular to the elongate direction of the recording medium 12before cut, which is hereinafter referred to as a width direction). Forexample, the recording head 36 has four rows of nozzles thatrespectively eject ink droplets of C (cyan), M (magenta), Y (yellow),and K (black), which are arranged so that the direction in which thenozzle rows extend corresponds to the width direction and so that theink ejecting direction is directed to a given recording position.

In the recording unit 20, while the scanning conveyer roller pairs 32and 34 scanning-convey the recording medium 12 in the directionperpendicular to the width direction, the droplet ejecting means forejecting ink droplets from each nozzle is modulation-driven according toimage data supplied from the control unit 26 described later, wherebyink droplets are ejected from the recording head 36 to form a full-colorimage, with four colors, on the surface of the recording medium 12 inaccordance with the image data.

In the present invention, the image recording process by ink jet is notlimited to that using a line head, but it can be an ink jet imagerecording process using a so-called serial head, where, the direction ofthe rows of nozzles coincides with the direction in which the recordingmedium 12 is moved, and the recording medium 12 is intermittently movedas the recording head scans (shuttles) in the direction perpendicular tothe direction of conveyance (in the example of FIG. 1, in the widthdirection of the recording medium 12).

Also, the present invention does not limit the image recording onto therecording medium 12 to the ink jet process, but any image recordingprocess can be employed. For example, the image recording may employelectrophotography. Or, it may use a digital photographic printer inwhich photographic paper (photosensitive material) is scanned andexposed with a light beam modulated according to an image to be recordedand then subjected to given wet development and drying process.Alternatively, the image recording process may be achieved by a methodin which photosensitive material (donor) is exposed with a light beammodulated according to an image to be recorded to form a latent imageand the image is thermally developed and transferred to an imagereceiving medium in the presence of image forming solvent.

The recording medium 12 on which an image is recorded is next fed to thecoating film laminating unit 22 (hereinafter referred to as laminatingunit 22) which has a laminating means 38, where the recording medium 12is laminated with a coating film 14.

The laminating means 38 is a laminating/bonding means of sheet-likematerials having positioning means, pressing rolls, etc., which furtherincludes means for drawing out the coating film 14, conveying means, acutter, etc.

In the example of FIG. 1, like the recording medium 12, the coating film14 is also prepared in the form of a long strip and wound to form acoating film roll 39, which is loaded in the laminating unit 22.

In the laminating means 38, drawing roller pair draws out the coatingfilm 14 from the coating film roll 39 and the cutter cuts it to the samesize as the recording medium. Then the recording medium 12 and thecoating film 14 are properly positioned, superposed (with an adhesiveetc. when needed), and pressed (and/or heated when needed), whereby thecoating film 14 is laminated on the surface of the recording medium 12.

As shown by dotted line in FIG. 1, like the medium rolls 28 describedearlier, a plurality of coating film rolls 39 of different coating films14 are prepared and loaded. In accordance with an instruction from thecontrol unit 26 as will be described later, the laminating unit 22 feedsthe specified coating film from the corresponding coating film roll 39and laminates it on the recording medium 12.

The individual coating films 14 differ in material, thickness, surfaceroughness, etc. As will be described later, expressible degrees of glossdiffer when even one of these factors differs. Therefore, in the presentinvention, coating films 14 differing in thickness, coating films 14differing in surface roughness, or coating films 14 differing in arefractive index, are treated as different kinds of coating films 14even when they are made of the same material. A single kind of coatingfilm 14 may be prepared, but, preparing two or more kinds of coatingfilms 14 is preferred. Also, the laminating unit 22 may be constructedto allow loading of only a single coating film roll 39 and then anoperator etc. will set an appropriate one.

In the present invention, the coating films 14 employed are not limitedto particular kinds, and any kinds of coating films can be used as longas they do not interfere with the appearance of the image recorded onthe recording medium 12.

For example, the coating film may be made of polyurethane resin asdisclosed in JP 10-34909 A, or silicone resin as disclosed in JP10-309846 A, or thermoplastic polyethylene resin as disclosed in JP2000-108454 A.

The thickness is not particularly limited and can be appropriatelydetermined depending on the material, preferably, in the range of 10 μmto 100 μm.

As will be described later, in the image forming method of the presentinvention, a thermal head 46 has a heating part (the surface of theglaze) with certain surface roughness and the surface of the coatingfilm 14 is processed by the thermal head 46 with locally controlledheating, whereby the surface roughness of the heating part of thethermal head 46 is transferred to the coating film 14. Thus the surfaceroughness of the coating film 14 is controlled differently in differentareas of the image, thereby providing glossiness according to thecontents of the image, e.g. objects in the image, so as to suitablyexpress texture.

While the image forming apparatus 10 of FIG. 1 forms the coating film 14on the recording medium 12 by laminating the sheet-like coating film 14on the image recording surface of the recording medium 12, the presentinvention is not limited to this method. For example, paint may beapplied on the recording medium 12 according to a target thickness anddried to form a coating film. A coating film may be formed by ejectingtransparent coating liquid, e.g. by ink jet.

Also, when needed, prior to the surface processing, a surface rougheningprocess may be applied to a coating film thus formed with paint.

A laminate 40 is obtained by laminating the recording medium 12 and thecoating film 14 together in the laminating unit 22. The laminate 40 isthen moved by a conveyer roller pair 42 to the surface processing unit24, where the coating film 14 is surface-processed. As a result, animage (a hard copy) according to the image forming method of theinvention is produced and carried by a discharging roller pair 44 to apaper discharge tray (not shown), for example.

The surface processing unit 24 includes the thermal head 46 and a platenroller 48.

The thermal head 46 has a heating part (glaze) in which heat generatingelements (heaters) formed of electrodes and heat generating resistorsetc. are arranged in one direction. The heat generating elements arearranged in the direction perpendicular to the direction in which theplaten roller 48 conveys the laminate 40 (that is, the width directioncoincides with the direction in which the element rows extend).

In the present invention, the thermal head 46 (surface processing means)performing surface processing is not required to have a very highresolution. For example, a resolution of about 50 dpi, which causes nounnaturalness when viewed, suffices. This reduces cost. Also, settingthe resolution of the recording head 36 (recording means) at an integralmultiple of the resolution of the thermal head 46 simplifies surfaceprocessing control.

In the surface processing unit 24, as in an image recording process by aknown thermal recording printer, the laminate 40, nipped by the thermalhead 46 (its heating/pressing part) and the platen roller 48, isconveyed in the elongate direction (the direction perpendicular to thewidth direction) as the platen roller 48 rotates. During the conveyance,the heat generating elements of the thermal head 46 aremodulation-driven according to surface processing conditions (heatingtemperature) supplied from the control unit 26.

During this process, as the heating part (pressing part) of the thermalhead 46 has a certain degree of surface roughness (surface property),the surface roughness is transferred to the surface of the coating film14 by heating/pressing. When the heating temperature is low, the surfaceroughness of the heating part of the thermal head 46 is transferred notsufficiently but dully to the surface of the coating film 14 (that is, alower degree of surface roughness, relative to the surface roughness ofthe heating part, is transferred to the surface of the coating film 14).

Thus, different areas of the surface of the coating film 14 can beheated/pressed under different heating conditions by locally controllingthe heating by the thermal head 46, so as to form (transfer) desiredsurface roughness on the surface of the coating film 14. In the imageforming apparatus 10 of FIG. 1, the degrees of surface roughness inindividual areas of the image are controlled according to glossinessdata described later, whereby glossiness is given to individual areas ofthe image in conformity with the contents of the image, e.g. objects inthe image (the image recorded in the recording unit 20).

In this invention, as shown by dotted line in FIG. 1, a plurality ofthermal heads 46 having heating parts with different degrees of surfaceroughness may be prepared, and then a suitable thermal head 46 can beselected according to the target surface roughness of the coating film14. In this case, the control unit 26 selects a thermal head 46 that canachieve the target range of surface roughness, according to a relationbetween the coating film and surface roughness, and the like, as will bedescribed later.

This embodiment of the present invention adopts a thermal head 46 whichcan serve both as a heating means and a pressing means. However, this isnot the sole case and a heating means and a pressing means mayseparately be provided. In such cases, a coating film 14 is heated bythe heating means, and subsequently, a pressing member is pressedagainst a surface of the coating film 14.

The control unit 26, provided to control the entire image formingapparatus 10, sets (selects) a coating film 14 in accordance withsupplied image data and glossiness data, while referring to a materialsetting table which will be described later, and then it sendsinstructions to the feeding unit 16 and the laminating unit 22.

The control unit 26 also supplies the image data to the recording head36. Further, using a processing condition table described later, thecontrol unit 26 sets (determines) surface processing conditions,including conditions for driving the thermal head 46, and supplies theconditions to the thermal head 46 etc.

In the present invention, the image data is two-dimensional image datathat conforms to the employed image recording process, and therefore, inthe example of FIG. 1, it is C, M, Y, and K image data conforming to theimage recording process performed by the recording head 36.

The glossiness data is two-dimensional glossiness data for individualareas of the image reproduced by the image data supplied to the controlunit 26 together with the glossiness data. For example, as shown in FIG.2, when the image (the image reproduced by the image data) contains atable 60, the glossiness data may indicate a degree of gloss of 25% forthe area of the table 60 and a degree of gloss of 10% for the backgroundarea. In the image of FIG. 2, when a (CD) case is placed on the table 60and a CD is placed thereon, the data may indicate a degree of gloss of25% for the area of the table 60, a degree of gloss of 30% for the areaof the case, a degree of gloss of 40% for the area of the CD, and adegree of gloss of 10% for the background area.

Note that, in the present invention, the glossiness data is not limitedto data that directly indicates glossiness of individual areas.

For example, the degrees of gloss for various materials of objects maybe determined in advance and set in the control unit 26, as a degree ofgloss of 40% for metal, a degree of gloss of 25% for wood, a degree ofgloss of 10% for cloth, and a degree of gloss of 15% for paper. Theninformation showing the materials of individual areas is supplied as theglossiness data and the control unit 26 knows the degrees of gloss forthe individual areas according to the material information.

Also, in the invention, the glossiness can be measured and theglossiness data can be generated by considering light absorption at thecoating film 14 and reflection at the recording medium 12, according to,e.g. the JIS Z 8741 mirror-surface glossiness measurement method.

The operation of the image forming apparatus 10 is now described to showmore details of the image forming method of the present invention.

As schematically shown in FIG. 3, with a hard copy formed of the imagerecording medium 12 (base/image recording layer)/coating film 14,produced by the image forming apparatus 10 of FIG. 1, a physical factorof the surface glossiness (reflected light I_(out) with the incidentlight I_(in)) is chiefly determined by the refractive index, n, of thecoating film 14, the film thickness, d, of the coating film 14, and thesurface roughness, Ra, of the coating film 14. While, more strictly, thesurface glossiness is affected also by the surface refractive index andthe thickness of the image recording medium 12 (the image recordinglayer), the effect is usually visually negligible.

In the present invention, as shown in FIG. 4, first, a coating film 14is selected (its material, thickness, surface roughness, etc. are set: amaterial setting step; S1) in order to express desired degrees of glosscorresponding to the contents in individual areas of the image, e.g. thetable 60 and the background, and next, surface processing conditions areset (a condition setting step; S2) to form desired surface roughness onthe surface of the coating film 14, and then surface processing isapplied to the coating film 14 (a processing step; S3).

As described above, when image data for the recorded image and thecorresponding glossiness data are supplied to the control unit 26, thenthe control unit 26 supplies the image data to the recording unit 20 andselects a coating film 14 to be employed, according to the glossinessdata.

The control unit 26 contains a material setting table as shown in FIG.5A, which shows the relation between surface roughness Ra [μm] andglossiness [%] for each coating film 14. When supplied with theglossiness data, the control unit 26 knows the range of glossiness thatshould be expressed on the image (hard copy) and refers to the materialsetting table to select one of a plurality of coating films 14 that isable to express the target glossiness.

For example, as shown in FIG. 5A, with two kinds of coating films 14made of the same material and having the same surface roughness butdifferent thicknesses (50 μm and 100 μm), and with glossiness dataindicating 25% gloss for the table 60 area and 10% gloss for thebackground in an image as shown in FIG. 2, then the control unit 26refers to the material setting table and selects the 100-μm-thickcoating film 14 that can express both degrees of gloss, and instructsthe laminating unit 22 to use this coating film 14.

When, considering the target glossiness, a plurality of coating films 14satisfy conditions determined in the surface processing conditionsetting step described later, i.e. when a plurality of coating films 14can be employed, then the selection may be made arbitrarily.

Next, with the coating film 14 thus selected, and according to theglossiness data, the control unit 26 refers again to the materialsetting table to set surface roughness Ra for expressing the targetglossiness for each area of the image.

That is to say, for instance, with the example of FIG. 2, since theglossiness data indicates 25% gloss for the area of the table 60 and 10%gloss for the background area, the control unit 26 refers to thematerial setting table of FIG. 5A and sets the surface roughness Ra at 7μm for the 25%-gloss table area and sets the surface roughness Ra at 20μm for the 10%-gloss background area.

Then, according to the glossiness data, i.e. according to the values ofsurface roughness Ra thus set, the control unit 26 determines, for eachimage area, a condition for the surface processing by the thermal head46 so that the set surface roughness of the coating film 14 can beachieved.

The control unit 26 contains a condition setting table as shown in FIG.5B for each coating film 14, which shows the relation between thesurface roughness Ra of the coating film 14 and heating temperature T [°C.] for the surface processing by the thermal head 46. In this example,referring to the condition setting table, when using a thermal head 46having a heating part with a surface roughness of 40 μm, the heatingtemperature is set at 80° C. for the area of surface roughness Ra of 20μm (gloss of 10%) to form the target roughness and the heatingtemperature is set at 52° C. for the area of surface roughness Ra of 7μm (gloss of 25%) to form the target roughness.

Next, the control unit 46 supplies the heating temperature informationfor each image area to the surface processing unit 24.

When the employed coating film 14 and surface processing conditions(heating temperatures) by the thermal head 46 are thus determined andthe information is supplied to the relevant units, then, first, thefeeding roller pair 30 in the feeding unit 16 draws out the specifiedrecording medium 12 from the corresponding medium roll 28 and feeds itto the cutter 18, and then the cutter 18 cuts the recording medium 12 tothe size of the image to be formed as described earlier.

Next, in the recording unit 20, as the scanning conveyer roll pairs 32and 34 scan-convey the recording medium 12, the recording head 36records a full-color image by ink jet on the surface of the recordingmedium 12 in accordance with the supplied image data.

Next, in the laminating unit 22, the laminating means 38 draws out theselected coating film 14 from the corresponding coating film roll 39,cuts the coating film 14 to the size of the image to be formed, andlaminates/bonds it on the surface of the recording medium 12 on whichimage is recorded.

Next, the conveyer roller pair 42 passes the laminate 40 of therecording medium 12 and the coating film 14 to the surface processingunit 24. In the surface processing unit 24, with the laminate 40 beingnipped and conveyed by the thermal head 46 (heating part) and the platenroller 48, the thermal head 46 (individual heat generating elements) isdriven according to the supplied heating temperature (surface processingconditions) to apply surface processing to the coating film 14. Thus thesurface roughness of the heating part of the thermal head 46 can betransferred to the surface of the coating film 14 at the set heatingtemperatures to provide the surface of the coating film 14 with surfaceroughness corresponding to the target glossiness.

Then, with the coating film 14 thus surface-processed, the laminate 40(i.e. an image (a hard copy) produced by the image forming method of thepresent invention) is discharged by the discharging roller pair 44 to adischarge tray (not shown).

In this example, the surface processing of the coating film 14 iscontrolled by controlling the temperature of the thermal head 46(heating means).

However, the present invention is not limited to this method ofcontrolling the surface processing by the thermal head 46. For example,various processing conditions, such as heating/pressuring time, pressingforce, surface roughness of the heating part, etc., can be controlled tocontrol the surface roughness of the coating film 14 according to theglossiness data.

Needless to say, a plurality of factors of processing conditions,including heating temperature, can be controlled in combination.

For example, by setting some levels of the pressing force of the thermalhead 46, and with a condition setting table created on the basis ofcombinations of the pressing force levels and coating films 14, thepressing force of the thermal head 46 may be set (selected) inaccordance with the target glossiness (target surface roughness Ra), andthen surface processing conditions, such as heating temperature, can beset under the selected pressing force condition. Alternatively, with aplurality of thermal heads 46 having heating parts with differentlyroughened surfaces, and with a condition setting table based oncombinations of the thermal heads and coating films 14, a thermal head46 to be employed can be selected in accordance with the targetglossiness (target surface roughness Ra) and then surface processingconditions like heating temperature for each area can be set using thecondition setting table.

In any case, condition setting tables can be created by previouslyknowing, by experiment or by simulation, relations between processingconditions like pressing force and processing time and the surfaceroughness Ra of the coating film 14, and the condition setting tablesare set in the control unit 26.

While the image forming method and the image forming apparatus of thepresent invention have been described in detail, it is understood thatthe embodiments described above are illustrative and not restrictive andnumerous other modifications and variations can be devised withoutdeparting from the scope of the present invention.

For instance, in the example shown above, as the preferred embodiments,the glossiness data indicates different degrees of gloss for differentareas of an image according to the contents and the thermal head isthereby locally controlled to apply surface processing to areas of theimage under different conditions. However, the present invention is notlimited to this example but uniform glossiness data for the entire imagearea may be used to provide glossiness to the image by uniform surfaceprocessing to the entire image.

This example, too, is capable of providing glossiness suitable for thecontents of the image far more freely than conventional techniques byallowing selection of coating films and setting of surface processingconditions, thereby forming higher-quality image.

Also, in the illustrated example, a coating film having a smooth surfaceis formed on the recording medium and surface-processed according toglossiness data to roughen the surface. However, in the presentinvention, the method of forming irregularities on the coating film bysurface processing is not limited to this method. For example, in anopposite way, a coating film having a rough surface may be formed andprocessed, e.g. by heating, to reduce the irregularities, so as toobtain a coating film having surface roughness in conformity withglossiness data.

Furthermore, the method of roughening the coating film surface is notlimited to the above-described method using a thermal head. For example,the coating film may be roughened by forming indentations with a heatedneedle utilizing “Millipede”, an information recording techniquepresented by IBM.

1. An image forming method comprising: a recording step of recording animage on an image recording layer of an image recording medium accordingto image data; a material setting step of setting a coating film to beprovided on said image recording layer according to glossiness dataindicating glossiness of the image reproduced by said image data; acondition setting step of determining a condition of a surfaceprocessing of said coating film by considering said set coating film andaccording to said glossiness data; and a processing step of performingthe surface processing of said coating film in accordance with saiddetermined surface processing condition.
 2. The image forming methodaccording to claim 1, wherein said glossiness data indicates a degree ofgloss for each area of the reproduced image.
 3. The image forming methodaccording to claim 1, wherein said material setting step sets saidcoating film according to a table using said glossiness data and saidcoating film as parameters.
 4. The image forming method according toclaim 1, wherein the surface processing in said processing step isperformed by heating means for heating a surface of said coating filmand pressing means for pressing a pressing member against a surface ofsaid coating film, and wherein said condition setting step determinessaid surface processing condition according to a table using, asparameters, in addition to said glossiness data and said coating film,at least one of heating temperature by said heating means, heating timeby said heating means, pressing force by said pressing means, surfaceroughness of said pressing member, and pressing time by said pressingmeans.
 5. The image forming method according to claim 4, wherein saidheating means heats the surface of said coating film while locallycontrolling the heating.
 6. The image forming method according to claim1, wherein said recording step records said image at a resolution whichis an integral multiple of that of said surface processing. 7-12.(canceled)